Clinical and electrophysiological studies on sensory conduction mediated by the accessory rootlets of the human trigeminal nerve.

The authors present records of potentials evoked in the roots of the trigeminal nerve by stimulation of its cutaneous branches. Records were made during nine operations for tic douloureux in which the main sensory root of the trigeminal nerve was totally sectioned under the microscope by the transcerebellar route. In every case, the accessory (aberrant) and motor roots were easily identified and spared. Records before and after total main sensory root division showed persistence of evoked potentials in the aberrant and motor fibers. Partial preservation of sensation and blink reflex in these cases reinforced the impression that there is somatic sensory conduction through true aberrant sensory fibers running between the motor and main sensory roots.